Over-the-Air Digital TV with Linux

A review of some current state-of-the-art digital TV tuner cards, focusing on how well they support digital television in Linux.

My ten-year-old TV set gave out recently. Being a Linux geek, I use a
variety of open-source distributions on my notebook and desktop. So,
the demise of my TV was a great opportunity to see if I could watch
television on Linux instead of getting another TV set. It's just in time
too, because over-the-air television broadcasts in the US will convert
to all digital in February 2009. So, it was exciting to switch
over to digital TV on my desktop.

In my quest to understand the state of digital TV (DTV) on Linux, I
looked at digital TV tuner cards, antennas and accessories. I chose
to set up MythTV, and by the end of the entire experience, I had a
cool digital TV right on my Linux desktop with Picture-in-Picture and
remote control. It was enough high-definition (HD) TV to turn me into
a serious couch potato. I'm happy to report that Linux,
along with hardware support from digital TV tuner cards, video cards,
LCD monitors and rich software, such as MythTV, is ready for prime
time.

Digital TV Environment

For this review, I used a PC with an Intel Core 2 Duo 3GHz, with
4GB memory, an NVIDIA 8800 GT graphics card, and a 750GB SATA hard
disk. The display was a Samsung SyncMaster 245BW, with a resolution
of 1920x1200. I ran Ubuntu 7.10, with all the latest updates, as my
operating system. Using a powerful graphics card was essential for
viewing HD programs on a high-resolution, wide-screen display.

A good antenna also is a critical component of the DTV setup. I
tested both indoor and outdoor antennas, and discovered that the reception
improved dramatically when using an outdoor antenna. The reception
also improved with amplified indoor antennas. Standard indoor antennas
performed adequately only when positioned very carefully. Because HDTV
content is high-resolution (1920x1080), if your signal is weak, you may
see a lot of artifacts. Frequent artifacts result in a very poor viewing
experience. Hence, choosing an amplified indoor antenna or an outdoor
antenna is recommended. Standard-definition TV (SDTV) is not as high-resolution and has greater tolerance for weak broadcast signals. But,
even here a good antenna is essential.

I used MythTV (version 0.20.2) to view over-the-air DTV
channels. MythTV is an open-source home entertainment software application
for Linux and Mac OS. It has grown to become one of the most comprehensive,
feature-rich platforms for viewing and recording television programming from
over-the-air and cable broadcasts. I also used another open-source
software application called tvtime (version 1.0.2)
to view over-the-air analog NTSC channels.

So, what can we watch? There are a lot of over-the-air programs available in all
major US metropolitan areas. For example, ABC, CBS, FOX and NBC offer
standard and high-definition programming in addition to analog NTSC. In my
location, the San Francisco Bay area, local public broadcasting stations
(PBS) broadcast high-quality educational and topical content in HDTV
format from 5pm to 6am each day.

Digital Tuner Card Evaluation

To evaluate various digital tuner cards, I tested first whether the
hardware was recognized by Linux at boot time by checking the system
logs. If it wasn't recognized, I had to find and build a device driver
manually. Once this step was successful, I configured the tuner card
within MythTV. As a part of configuration, MythTV scans for channels
available in the broadcast area. On average, it took MythTV about seven
minutes to find more than 25 digital channels. Once the channels were found,
we were ready to watch digital TV.

I evaluated a range of digital tuners that included PCI, PCI Express
and USB bus types.

pcHDTV HD-5500

The pcHDTV HD-5500 is a PCI card and is the only hardware designed and
marketed to support Linux right out of the box. The HD-5500 supports
digital (ATSC), analog (NTSC) and unencrypted cable TV signals. This
low-profile PCI card provides a coaxial input for a TV antenna, a
stereo audio output jack for analog TV and a nine-pin port for an adapter
cable. The adapter cable provides inputs for S-Video and stereo audio, an
RCA video output, and an IR transmitter (to control a set-top box). pcHDTV
ships a CD with the HD-5500 tuner card, which includes drivers for 2.4 and
older 2.6 kernels, command-line tools to capture and manipulate digital
(ATSC) data streams and signals, and a version of the Xine video player
customized to support HDTV.

This tuner card worked out of the box—configuration was as easy as
installing the card into the PCI slot of my desktop test machine. Both the
digital (ATSC) and analog (NTSC) tuners on the hardware were recognized
right away and were fully functional at system bootup. Configuring the
tuner as a “DVB DTV capture card (v3.x)” in MythTV was simple. If I had
installed additional pcHDTV cards, I could have tested out multicard
features, such as Picture-in-Picture (PiP) in MythTV. pcHDTV claims you
can put up to four such cards in a single system.

The picture quality for both high-definition and standard-definition
programs was superb. To top it off, the whole idea of having an
end-to-end Linux DTV solution with a no-fuss setup and a great viewing
experience is just plain cool. The HD-5500 is an ideal choice for a
desktop Linux system. It would be nice to have a USB version for laptops
as well. A remote control, as offered by several other DTV tuner products,
would be icing on the cake.

I had the chance to catch up with pcHDTV's CEO, Jack Kelliher, by
e-mail (see the Interview with Jack Kelliher, CEO and Cofounder of pcHDTV
sidebar).

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